High polymer load polyolefin adhesive compositions

ABSTRACT

The present invention is related to adhesive compositions comprising about 50 to about 80 wt % of a polymer blend of at least two different propylene-based polymers, wherein the polymer blend has a melt viscosity of about 100 to about 6,000 cP and adhesive compositions comprising about 30 to about 60 wt % of a polymer blend of at least two different propylene-based polymers, wherein the polymer blend has a melt viscosity of about 6,000 cP to about 60,000 cP. When subjected to Temperature Rising Elution Fractionation, the polymer blend exhibits a first fraction that is soluble at −15° C. in xylene, the first fraction having an isotactic (mm) triad tacticity of about 70 mol % to about 90 mol %; and a second fraction that is insoluble or less soluble than the first fraction at −15° C. in xylene, the second fraction having an isotactic (mm) triad tacticity of about 85 mol % to about 98 mol %.

PRIORITY CLAIM TO RELATED APPLICATIONS

This application is a National Stage Application of InternationalApplication No. PCT/US2014/059250, filed Oct. 6, 2014, which claims thebenefit of 61/892,826, filed Oct. 18, 2013, the disclosures of which arefully incorporated herein by reference in their entirety.

FIELD OF INVENTION

The invention relates to a polyolefin adhesive composition comprising ahigh polymer load.

BACKGROUND

Adhesive composition components such as base polymers, tackifiers,waxes, and oils are customarily provided as separate components forformulation into hot melt adhesive (HMA) compositions. HMA compositionsfor nonwoven applications are used for construction and lamination,e.g., to attach nonwoven and other components together and to adhere thelayers of a material together. Nonwoven applications can include hygieneproducts such as baby diapers, adult diapers, incontinence products ordevices, absorbent articles, panty liners, and sanitary napkins. Innonwoven applications, HMA compositions are sought that provide adesired combination of physical properties such as stable adhesion overtime indicative of broad application temperature ranges, and machinecoatability. Machine coatability is a term well known in the art torefer to the robust application ability of an adhesive formulation on asubstrate, via a machine, requiring only minimal adjustment of machinesettings including machine speed and temperature. An adhesiveformulation having good machine coatability can reduce time andtherefore costs associated with the adhesive application process,because the adhesive formulation is versatile enough to be used on morethan one machine without many adjustments of the machine settlings. Poormachine coatability can result in web breaks of the adhesive formulationduring application of the adhesive at starting and stopping intervals ofthe machine, which can unfavorably impact line efficiency, and alsoresult in increased down time and high costs. HMAs having stable andconsistent adhesion over broad application temperatures are alsogenerally sought for nonwoven construction and lamination applications.

Exemplary base polymer compositions and methods of making polymercompositions for HMA applications are disclosed in U.S. Pat. Nos.7,294,681 and 7,524,910. Various polymers described in these patentsand/or produced by the methods disclosed in these patents have been soldby ExxonMobil Chemical Company as LINXAR™ polymers.

WO Publication No. 2013/134038 discloses a method for producing apolymer blend having at least two different propylene-based polymersproduced in parallel reactors. The multi-modal polymer blend has a Mw ofabout 10,000 g/mol to about 150,000 g/mol. When subjected to TemperatureRising Elution Fractionation, the polymer blend exhibits a firstfraction that is soluble at −15° C. in xylene, the first fraction havingan isotactic (mm) triad tacticity of about 70 mol % to about 90 mol %;and a second fraction that is insoluble or less soluble than the firstfraction at −15° C. in xylene, the second fraction having an isotactic(mm) triad tacticity of about 85 mol % to about 98 mol %.

Although many different types of polymers are known and have been usedin HMA formulations, there remains a need for a tackified adhesiveformulation that has high loading of the new based polymers to achieveequivalent or better adhesive performance attributes including stableadhesion over time indicative of broad application temperature ranges,and machine coatability, as compared to HMA formulations that arecurrently available.

Accordingly, the present invention is directed to an adhesivecomposition utilizing the new polymer blends, such that the adhesivecomposition has stable adhesion over time, indicative of broadapplication temperature ranges, and machine coatability. The adhesivecompositions described herein can be applied by contact and contactless,e.g. spray, application techniques. The adhesive compositions describedcan be used in nonwoven construction/lamination and nonwoven elasticapplications alike.

SUMMARY

The foregoing and/or other challenges are addressed by the methods andproducts disclosed herein.

In one aspect, a polymer blend and one or more tackifiers is providedfor use in an adhesive composition. The polymer blend includes a firstpropylene-based polymer, wherein the first propylene-based polymer is ahomopolymer of propylene or a copolymer of propylene and ethylene or aC₄ to C₁₀ alpha-olefin; a second propylene-based polymer, wherein thesecond propylene-based polymer is a homopolymer of propylene or acopolymer of propylene and ethylene or a C₄ to C₁₀ alpha-olefin; whereinthe second propylene-based polymer is different than the firstpropylene-based polymer. The polymer blend has a melt viscosity,measured at 190° C. of less than about 6,000 cP. When subjected toTemperature Rising Elution Fractionation, the polymer blend exhibits: afirst fraction that is soluble at −15° C. in xylene, the first fractionhaving an isotactic (mm) triad tacticity of about 70 mol % to about 90mol %; and a second fraction that is insoluble at −15° C. in xylene, thesecond fraction having an isotactic (mm) triad tacticity of about 85 mol% to about 98 mol %. The polymer blend is present in the amount of about50 to about 100 wt % of the adhesive composition.

In another aspect, a polymer blend and one or more tackifiers isprovided for use in an adhesive composition. The polymer blend includesa first propylene-based polymer, wherein the first propylene-basedpolymer is a homopolymer of propylene or a copolymer of propylene andethylene or a C₄ to C₁₀ alpha-olefin; a second propylene-based polymer,wherein the second propylene-based polymer is a homopolymer of propyleneor a copolymer of propylene and ethylene or a C₄ to C₁₀ alpha-olefin;wherein the second propylene-based polymer is different than the firstpropylene-based polymer. The polymer blend has a melt viscosity,measured at 190° C. of greater than or equal to about 6,000 cP. Whensubjected to Temperature Rising Elution Fractionation, the polymer blendexhibits: a first fraction that is soluble at −15° C. in xylene, thefirst fraction having an isotactic (mm) triad tacticity of about 70 mol% to about 90 mol %; and a second fraction that is insoluble at −15° C.in xylene, the second fraction having an isotactic (mm) triad tacticityof about 85 mol % to about 98 mol %. The polymer blend is present in theamount of about 30 to about 60 wt % of the adhesive composition.

These and other aspects of the present inventions are described ingreater detail in the following detailed description and are illustratedin the accompanying figures and tables.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts the peel strength of hot melt adhesive formulations overdifferent application temperatures.

FIG. 2 depicts the pump pressure and viscosities of hot melt adhesiveformulations over different application temperatures.

FIG. 3 depicts viscosity stability of hot melt adhesive formulations.

DETAILED DESCRIPTION

It has been discovered that high loading polymer blends to form adhesivecompositions results in advantageous properties for the adhesivecompositions including stable adhesion over time, which is indicative ofbroad application temperature ranges, and machine coatability,equivalent to or better than commercially available adhesives4. Theinventive adhesives may be produced using a new process platform that ismore robust and lacks many of the limitations and difficultiesassociated with the processes employed to make LINXAR™ polymers andthose disclosed in U.S. Pat. Nos. 7,294,681 and 7,524,910.

Advantageously, about 50 to about 100 wt % of one or more polymer blendsis used in adhesive formulations when the polymer blend has a meltviscosity of less than about 6,000 cP, for example, about 100 to about6,000 cP. About 30 to about 60 wt % of one or more polymer blends isused in adhesive formulations when the polymer blend has a meltviscosity of greater than or equal to about 6.000 cP, for example about6,000 to about 60,000 cP.

Advantageously, polymers used in the adhesive composition can beproduced using the new process platform that share many of thecharacteristics of the LINXAR™ polymers that make the LINXAR™ polymersexcellent polymers for use in adhesive applications. New polymers can beproduced using the new process platform that possess othercharacteristics that, although differentiate the polymers from theLINXAR™ polymers, are believed to contribute to the new polymers'excellent adhesive performance. These polymers may also, when subjectedto Temperature Rising Elution Fractionation, exhibit a first fractionthat is soluble at −15° C. in xylene, and a second fraction that isinsoluble or less soluble than the first fraction at −15° C. in xylene.The first fraction may have an isotactic (mm) triad tacticity of about70 mol % to about 90 mol %, and the second fraction may have anisotactic (mm) triad tacticity of about 85 mol % to about 98 mol %. Inpreferred embodiments, portions of each polymer of the polymer blend arerepresented in each fraction.

A. Methods of Preparing Polyolefin Adhesive Components and Compositions

A solution polymerization process for preparing a polyolefin adhesivecomponent is generally performed by a system that includes a firstreactor, a second reactor in parallel with the first reactor, aliquid-phase separator, a devolatilizing vessel, and a pelletizer. Thefirst reactor and second reactor may be, for example, continuousstirred-tank reactors.

The first reactor may receive a first monomer feed, a second monomerfeed, and a catalyst feed. The first reactor may also receive feeds of asolvent and an activator. The solvent and/or the activator feed may becombined with any of the first monomer feed, the second monomer feed, orcatalyst feed or the solvent and activator may be supplied to thereactor in separate feed streams. A first polymer is produced in thefirst reactor and is evacuated from the first reactor via a firstproduct stream. The first product stream comprises the first polymer,solvent, and any unreacted monomer.

In any embodiment, the first monomer in the first monomer feed may bepropylene and the second monomer in the second monomer feed may beethylene or a C₄ to C₁₀ olefin. In any embodiment, the second monomermay be ethylene, butene, hexene, and octene. Generally, the choice ofmonomers and relative amounts of chosen monomers employed in the processdepends on the desired properties of the first polymer and final polymerblend. For adhesive compositions, ethylene and hexene are particularlypreferred comonomers for copolymerization with propylene. In anyembodiment, the relative amounts of propylene and comonomer supplied tothe first reactor may be designed to produce a polymer that ispredominantly propylene, i.e., a polymer that is more than 50 mol %propylene. In another embodiment, the first reactor may produce ahomopolymer of propylene.

The second reactor may receive a third monomer feed of a third monomer,a fourth monomer feed of a fourth monomer, and a catalyst feed of asecond catalyst. The second reactor may also receive feeds of a solventand activator. The solvent and/or the activator feed may be combinedwith any of the third monomer feed, the fourth monomer feed, or secondcatalyst feed, or the solvent and activator may be supplied to thereactor in separate feed streams. A second polymer is produced in thesecond reactor and is evacuated from the second reactor via a secondproduct stream. The second product stream comprises the second polymer,solvent, and any unreacted monomer.

In any embodiment, the third monomer may be propylene and the fourthmonomer may be ethylene or a C₄ to C₁₀ olefin. In any embodiment, thefourth monomer may be ethylene, butene, hexene, and octene. In anyembodiment, the relative amounts of propylene and comonomer supplied tothe second reactor may be designed to produce a polymer that ispredominantly propylene, i.e., a polymer that is more than 50 mol %propylene. In another embodiment, the second reactor may produce ahomopolymer of propylene.

Preferably, the second polymer is different than the first polymer. Thedifference may be measured, for example, by the comonomer content, heatof fusion, crystallinity, branching index, weight average molecularweight, and/or polydispersity of the two polymers. In any embodiment,the second polymer may comprise a different comonomer than the firstpolymer or one polymer may be a homopolymer of propylene and the otherpolymer may comprise a copolymer of propylene and ethylene or a C₄ toC₁₀ olefin. For example, the first polymer may comprise apropylene-ethylene copolymer and the second polymer may comprise apropylene-hexene copolymer. In any embodiment, the second polymer mayhave a different weight average molecular weight (Mw) than the firstpolymer and/or a different melt viscosity than the first polymer.Furthermore, in any embodiment, the second polymer may have a differentcrystallinity and/or heat of fusion than the first polymer. Specificexamples of the types of polymers that may be combined to produceadvantageous blends are described in greater detail herein.

It should be appreciated that any number of additional reactors may beemployed to produce other polymers that may be integrated with (e.g.,grafted) or blended with the first and second polymers. In anyembodiment, a third reactor may produce a third polymer. The thirdreactor may be in parallel with the first reactor and second reactor orthe third reactor may be in series with one of the first reactor andsecond reactor.

Further description of exemplary methods for polymerizing the polymersdescribed herein may be found in U.S. Pat. No. 6,881,800, which isincorporated by reference herein.

The first product stream and second product stream may be combined toproduce a blend stream. For example, the first product stream and secondproduct stream may supply the first and second polymer to a mixingvessel, such as a mixing tank with an agitator.

The blend stream may be fed to a liquid-phase separation vessel toproduce a polymer rich phase and a polymer lean phase. The polymer leanphase may comprise the solvent and be substantially free of polymer. Atleast a portion of the polymer lean phase may be evacuated from theliquid-phase separation vessel via a solvent recirculation stream. Thesolvent recirculation stream may further include unreacted monomer. Atleast a portion of the polymer rich phase may be evacuated from theliquid-phase separation vessel via a polymer rich stream.

In any embodiment, the liquid-phase separation vessel may operate on theprinciple of Lower Critical Solution Temperature (LCST) phaseseparation. This technique uses the thermodynamic principle of spinodaldecomposition to generate two liquid phases; one substantially free ofpolymer and the other containing the dissolved polymer at a higherconcentration than the single liquid feed to the liquid-phase separationvessel.

Employing a liquid-phase separation vessel that utilizes spinodaldecomposition to achieve the formation of two liquid phases may be aneffective method for separating solvent from multi-modal polymer blends,particularly in cases in which one of the polymers of the blend has aweight average molecular weight less than 100,000 g/mol, and even moreparticularly between 10,000 g/mol and 60,000 g/mol. The concentration ofpolymer in the polymer lean phase may be further reduced by catalystselection. Catalysts of Formula I (described below), particularlydimethylsilyl bis(2-methyl-4-phenylindenyl) zirconium dichloride,dimethylsilyl bis(2-methyl-5-phenylindenyl) hafnium dichloride,dimethylsilyl bis(2-methyl-4-phenylindenyl) zirconium dimethyl, anddimethylsilyl bis(2-methyl-4-phenylindenyl) hafnium dimethyl were foundto be a particularly effective catalysts for minimizing theconcentration of polymer in the lean phase. Accordingly, in anyembodiment, one, both, or all polymers may be produced using a catalystof Formula I, particularly dimethylsilyl bis(2-methyl-4-phenylindenyl)zirconium dichloride, dimethylsilyl bis(2-methyl-4-phenylindenyl)hafnium dichloride, dimethylsilyl bis(2-methyl-4-phenylindenyl)zirconium dimethyl, and dimethylsilyl bis(2-methyl-4-phenylindenyl)hafnium dimethyl.

Upon exiting the liquid-phase separation vessel, the polymer rich streammay then be fed to a devolatilizing vessel for further polymer recovery.In any embodiment, the polymer rich stream may also be fed to a lowpressure separator before being fed to the inlet of the devolatilizingvessel. While in the vessel, the polymer composition may be subjected toa vacuum in the vessel such that at least a portion of the solvent isremoved from the polymer composition and the temperature of the polymercomposition is reduced, thereby forming a second polymer compositioncomprising the multi-modal polymer blend and having a lower solventcontent and a lower temperature than the polymer composition as thepolymer composition is introduced into the vessel. The polymercomposition may then be discharged from the outlet of the vessel via adischarge stream.

The cooled discharge stream may then be fed to a pelletizer where themulti-modal polymer blend is then discharged through a pelletization dieas formed pellets. Pelletization of the polymer may be by an underwater,hot face, strand, water ring, or other similar pelletizer. Preferably anunderwater pelletizer is used, but other equivalent pelletizing unitsknown to those skilled in the art may also be used. General techniquesfor underwater pelletizing are known to those of ordinary skill in theart.

WO Publication No. 2013/134038 generally describes the method ofpreparing polyolefin adhesive components and compositions. The contentsof WO Publication No. 2013/134038 and its parent application U.S. PatentApplication Ser. No. 61/609,020 filed Mar. 9, 2012, are bothincorporated herein in their entirety.

B. Polymers

Preferred polymers are semi-crystalline propylene-based polymers. In anyembodiment, the polymers may have a relatively low molecular weight,preferably about 150,000 g/mol or less. In any embodiment, the polymermay comprise a comonomer selected from the group consisting of ethyleneand linear or branched C₄ to C₂₀ olefins and diolefins. In anyembodiment, the comonomer may be ethylene or a C₄ to C₁₀ olefin.

The term “polymer” as used herein includes, but is not limited to,homopolymers, copolymers, interpolymers, terpolymers, etc. and alloysand blends thereof. Further, as used herein, the term “copolymer” ismeant to include polymers having two or more monomers, optionally withother monomers, and may refer to interpolymers, terpolymers, etc. Theterm “polymer” as used herein also includes impact, block, graft, randomand alternating copolymers. The term “polymer” shall further include allpossible geometrical configurations unless otherwise specificallystated. Such configurations may include isotactic, syndiotactic andrandom symmetries. The term “polymer blend” as used herein includes, butis not limited to a blend of one or more polymers prepared in solutionor by physical blending, such as melt blending.

“Propylene-based” or “predominantly propylene-based” as used herein, ismeant to include any polymer comprising propylene, either alone or incombination with one or more comonomers, in which propylene is the majorcomponent (i.e., greater than 50 mol % propylene).

In any embodiment, one or more polymers of the blend may comprise one ormore propylene-based polymers, which comprise propylene and from about 2mol % to about 30 mol % of one or more comonomers selected from C₂ andC₄-C₁₀ α-olefins. In any embodiment, the α-olefin comonomer units mayderive from ethylene, butene, pentene, hexene, 4-methyl-1-pentene,octene, or decene. The embodiments described below are discussed withreference to ethylene and hexene as the α-olefin comonomer, but theembodiments are equally applicable to other copolymers with otherα-olefin comonomers. In this regard, the copolymers may simply bereferred to as propylene-based polymers with reference to ethylene orhexene as the α-olefin.

In any embodiment, the one or more polymers of the blend may include atleast about 5 mol %, at least about 6 mol %, at least about 7 mol %, orat least about 8 mol %, or at least about 10 mol %, or at least about 12mol % ethylene-derived or hexene-derived units. In those or otherembodiments, the copolymers may include up to about 30 mol %, or up toabout 25 mol %, or up to about 22 mol %, or up to about 20 mol %, or upto about 19 mol %, or up to about 18 mol %, or up to about 17 mol %ethylene-derived or hexene-derived units, where the percentage by moleis based upon the total moles of the propylene-derived and α-olefinderived units. Stated another way, the propylene-based polymer mayinclude at least about 70 mol %, or at least about 75 mol %, or at leastabout 80 mol %, or at least about 81 mol % propylene-derived units, orat least about 82 mol % propylene-derived units, or at least about 83mol % propylene-derived units; and in these or other embodiments, thecopolymers may include up to about 95 mol %, or up to about 94 mol %, orup to about 93 mol %, or up to about 92 mol %, or up to about 90 mol %,or up to about 88 mol % propylene-derived units, where the percentage bymole is based upon the total moles of the propylene-derived andalpha-olefin derived units. In any embodiment, the propylene-basedpolymer may comprise from about 5 mol % to about 25 mol %ethylene-derived or hexene-derived units, or from about 8 mol % to about20 mol % ethylene-derived or hexene-derived units, or from about 12 mol% to about 18 mol % ethylene-derived or hexene-derived units.

The one or more polymers of the blend of one or more embodiments arecharacterized by a melting point (Tm), which can be determined bydifferential scanning calorimetry (DSC). For purposes herein, themaximum of the highest temperature peak is considered to be the meltingpoint of the polymer. A “peak” in this context is defined as a change inthe general slope of the DSC curve (heat flow versus temperature) frompositive to negative, forming a maximum without a shift in the baselinewhere the DSC curve is plotted so that an endothermic reaction would beshown with a positive peak.

In any embodiment, the Tm of the one or more polymers of the blend (asdetermined by DSC) may be less than about 130° C., or less than about120° C., or less than about 115° C., or less than about 110° C., or lessthan about 100° C., or less than about 90° C. In any embodiment, the Tmof the one or more polymers of the blend may be greater than about 25°C., or greater than about 30° C., or greater than about 35° C., orgreater than about 40° C.

In one or more embodiments, the first crystallization temperature (Tc1)of the polymer blend (as determined by DSC) is less than about 110° C.,or less than about 90° C., or less than about 80° C., or less than about70° C., or less than about 60° C., or less than about 50° C., or lessthan about 40° C., or less than about 30° C. or less than about 20° C.,or less than about 10° C. In the same or other embodiments, the Tc1 ofthe polymer is greater than about 0° C., or greater than about 5° C., orgreater than about 10° C., or greater than about 15° C., or greater thanabout 20° C. In any embodiment, the Tc1 lower limit of the polymer maybe 0° C., 5° C., 10° C. 20° C., 30° C., 40° C., 50° C., 60° C., and 70°C.; and the Tc1 upper limit temperature may be 100° C., 90° C., 80° C.,70° C., 60° C., 50° C., 40° C., 30° C. 25° C., and 20° C. with rangesfrom any lower limit to any upper limit being contemplated.

In one or more embodiments, the second crystallization temperature (Tc2)of the polymer (as determined by DSC) is less than about 100° C., orless than about 90° C., or less than about 80° C., or less than about70° C., or less than about 60° C., or less than about 50° C., or lessthan about 40° C., or less than about 30° C., or less than about 20° C.,or less than about 10° C. In the same or other embodiments, the Tc2 ofthe polymer is greater than about 0° C., or greater than about 5° C., orgreater than about 10° C., or greater than about 15° C., or greater thanabout 20° C. In any embodiment, the Tc2 lower limit of the polymer maybe 0° C., 5° C., 10° C., 20° C., 30° C. 40° C., 50° C., 60° C., and 70°C.; and the Tc2 upper limit temperature may be 120° C., 110° C., 100°C., 90° C., 80° C., 70° C., 60° C., 50° C., 40° C., 30° C., 25° C., and20° C. with ranges from any lower limit to any upper limit beingcontemplated.

The polymers suitable for use herein are said to be “semi-crystalline”,meaning that in general they have a relatively low crystallinity. Theterm “crystalline” as used herein broadly characterizes those polymersthat possess a high degree of both inter and intra molecular order, andwhich preferably melt higher than 110° C., more preferably higher than115° C., and most preferably above 130° C. A polymer possessing a highinter and intra molecular order is said to have a “high” level ofcrystallinity, while a polymer possessing a low inter and intramolecular order is said to have a “low” level of crystallinity.Crystallinity of a polymer can be expressed quantitatively, e.g., interms of percent crystallinity, usually with respect to some referenceor benchmark crystallinity. As used herein, crystallinity is measuredwith respect to isotactic polypropylene homopolymer. Preferably, heat offusion is used to determine crystallinity. Thus, for example, assumingthe heat of fusion for a highly crystalline polypropylene homopolymer is190 J/g, a semi-crystalline propylene copolymer having a heat of fusionof 95 J/g will have a crystallinity of 500/%. The term “crystallizable”as used herein refers to those polymers which can crystallize uponstretching or annealing. Thus, in certain specific embodiments, thesemi-crystalline polymer may be crystallizable. The semi-crystallinepolymers used in specific embodiments of this invention preferably havea crystallinity of from 2% to 65% of the crystallinity of isotaticpolypropylene. In further embodiments, the semi-crystalline polymers mayhave a crystallinity of from about 3% to about 40%, or from about 4% toabout 30%, or from about 5% to about 25% of the crystallinity ofisotactic polypropylene.

The semi-crystalline polymer can have a level of isotacticity expressedas percentage of isotactic triads (three consecutive propylene units),as measured by ¹³C NMR, of 75 mol % or greater, 80 mol % or greater, 85mol % or greater, 90 mol % or greater, 92 mol % or greater, 95 mol % orgreater, or 97 mol % or greater. In one or more embodiments, the triadtacticity may range from about 75 mol % to about 99 mol %, or from about80 mol % to about 99 mol %, or from about 85 mol % to about 99 mol %, orfrom about 90 mol % to about 99 mol %, or from about 90 mol % to about97 mol %, or from about 80 mol % to about 97 mol %. Triad tacticity isdetermined by the methods described in U.S. Patent ApplicationPublication No. 2004/0236042.

The semi-crystalline polymer may have a tacticity index m/r ranging froma lower limit of 4, or 6 to an upper limit of 10, or 20, or 25. Thetacticity index, expressed herein as “m/r”, is determined by ¹³C nuclearmagnetic resonance (“NMR”). The tacticity index m/r is calculated asdefined by H. N. Cheng in 17 MACROMOLECULES, 1950 (1984), incorporatedherein by reference. The designation “m” or “r” describes thestereochemistry of pairs of contiguous propylene groups, “m” referringto meso and “r” to racemic. An m/r ratio of 1.0 generally describes anatactic polymer, and as the m/r ratio approaches zero, the polymer isincreasingly more syndiotactic. The polymer is increasingly isotactic asthe m/r ratio increases above 1.0 and approaches infinity.

In one or more embodiments, the semi-crystalline polymer may have adensity of from about 0.85 g/cm³ to about 0.92 g/cm³, or from about 0.86g/cm³ to about 0.90 g/cm³, or from about 0.86 g/cm³ to about 0.89 g/cm³at room temperature and determined according to ASTM D-792. As usedherein, the term “room temperature” is used to refer to the temperaturerange of about 20° C. to about 23.5° C.

In one or more embodiments, the semi-crystalline polymer can have aweight average molecular weight (Mw) of from about 5,000 to about500,000 g/mol, or from about 7,500 to about 300,000 g/mol, or from about10,000 to about 200.000 g/mol, or from about 25,000 to about 175,000g/mol.

Weight-average molecular weight, M_(w), molecular weight distribution(MWD) or M_(w)/M_(n) where M_(n) is the number-average molecular weight,and the branching index, g′(vis), are characterized using a HighTemperature Size Exclusion Chromatograph (SEC), equipped with adifferential refractive index detector (DRI), an online light scatteringdetector (LS), and a viscometer. Experimental details not shown below,including how the detectors are calibrated, are described in: T. Sun, P.Brant, R. R. Chance, and W. W. Graessley, Macromolecules, Volume 34,Number 19, pp. 6812-6820, 2001.

Solvent for the SEC experiment is prepared by dissolving 6 g ofbutylated hydroxy toluene as an antioxidant in 4 L of Aldrich reagentgrade 1,2,4 trichlorobenzene (TCB). The TCB mixture is then filteredthrough a 0.7 μm glass pre-filter and subsequently through a 0.1 μmTeflon filter. The TCB is then degassed with an online degasser beforeentering the SEC. Polymer solutions are prepared by placing the drypolymer in a glass container, adding the desired amount of TCB, thenheating the mixture at 160° C. with continuous agitation for about 2 hr.All quantities are measured gravimetrically. The TCB densities used toexpress the polymer concentration in mass/volume units are 1.463 g/mL atroom temperature and 1.324 g/mL at 135° C. The injection concentrationranges from 1.0 to 2.0 mg/mL, with lower concentrations being used forhigher molecular weight samples. Prior to running each sample the DRIdetector and the injector are purged. Flow rate in the apparatus is thenincreased to 0.5 mL/min, and the DRI was allowed to stabilize for 8-9 hrbefore injecting the first sample. The LS laser is turned on 1 to 1.5 hrbefore running samples.

The concentration, c, at each point in the chromatogram is calculatedfrom the baseline-subtracted DRI signal, I_(DRI), using the followingequation:c=K _(DRI) I _(DRI)/(dn/dc)where K_(DRI) is a constant determined by calibrating the DRI, and dn/dcis the same as described below for the LS analysis. Units on parametersthroughout this description of the SEC method are such thatconcentration is expressed in g/cm³, molecular weight is expressed inkg/mol, and intrinsic viscosity is expressed in dL/g.

The light scattering detector used is a Wyatt Technology HighTemperature mini-DAWN. The polymer molecular weight, M, at each point inthe chromatogram is determined by analyzing the LS output using the Zimmmodel for static light scattering (M. B. Huglin, LIGHT SCATTERING FROMPOLYMER SOLUTIONS, Academic Press, 1971):[K _(o) c/ΔR(θ,c)]=[1/MP(θ)]+2A ₂ cwhere ΔR(θ) is the measured excess Rayleigh scattering intensity atscattering angle θ, c is the polymer concentration determined from theDRI analysis, A₂ is the second virial coefficient, P(θ) is the formfactor for a monodisperse random coil (described in the abovereference), and K_(o) is the optical constant for the system:

$K_{o} = \frac{4\pi^{2}{n^{2}\left( {{dn}/{dc}} \right)}^{2}}{\lambda^{4}N_{A}}$in which N_(A) is the Avogadro's number, and dn/dc is the refractiveindex increment for the system. The refractive index, n=1.500 for TCB at135° C. and λ=690 nm. In addition, A₂=0.0015 and dn/dc=0.104 forethylene polymers, whereas A₂=0.0006 and dn/dc=0.104 for propylenepolymers.

The molecular weight averages are usually defined by considering thediscontinuous nature of the distribution in which the macromoleculesexist in discrete fractions i containing N_(i) molecules of molecularweight M_(i). The weight-average molecular weight. M_(w), is defined asthe sum of the products of the molecular weight M_(i) of each fractionmultiplied by its weight fraction w_(i):M _(w) =Σw _(i) M _(i)=(ΣN _(i) M _(i) ² /ΣN _(i) M _(i))since the weight fraction w_(i) is defined as the weight of molecules ofmolecular weight M_(i) divided by the total weight of all the moleculespresent:w _(i) =N _(i) M _(i) /ΣN _(i) M _(i)

The number-average molecular weight, M_(n), is defined as the sum of theproducts of the molecular weight M_(i) of each fraction multiplied byits mole fraction x_(i):M _(n) =Σx _(i) M _(i) M=ΣN _(i) M _(i) /ΣN _(i)since the mole fraction x₁ is defined as N_(i) divided by the totalnumber of moleculesx _(i) =N _(i) /ΣN _(i)

In the SEC, a high temperature Viscotek Corporation viscometer is used,which has four capillaries arranged in a Wheatstone bridge configurationwith two pressure transducers. One transducer measures the totalpressure drop across the detector, and the other, positioned between thetwo sides of the bridge, measures a differential pressure. The specificviscosity, η_(s), for the solution flowing through the viscometer iscalculated from their outputs. The intrinsic viscosity, [η], at eachpoint in the chromatogram is calculated from the following equation:η_(s) =c[η]+0.3(c[η])²where c was determined from the DRI output.

The branching index (g′, also referred to as g′(vis)) is calculatedusing the output of the SEC-DRI-LS-VIS method as follows. The averageintrinsic viscosity, [η]_(avg), of the sample is calculated by:

$\lbrack\eta\rbrack_{avg} = \frac{\sum{c_{i}\lbrack\eta\rbrack}_{i}}{\sum c_{i}}$where the summations are over the chromatographic slices, i, between theintegration limits.

The branching index g′ is defined as:

$g^{\prime} = \frac{\lbrack\eta\rbrack_{avg}}{{kM}_{v}^{\alpha}}$where k=0.000579 and α=0.695 for ethylene polymers; k=0.0002288 andα=0.705 for propylene polymers; and k=0.00018 and α=0.7 for butenepolymers.

M_(v) is the viscosity-average molecular weight based on molecularweights determined by the LS analysis:M _(v)=(Σc _(i) M _(i) ^(α) /Σc _(i))^(1/α)

In one or more embodiments, the semi-crystalline polymer may have aviscosity (also referred to a Brookfield viscosity or melt viscosity),measured at 190° C. and determined according to ASTM D-3236 from about100 cP to about 500,000 cP, or from about 100 to about 100,000 cP, orfrom about 100 to about 50,000 cP, or from about 100 to about 25,000 cP,or from about 100 to about 15,000 cP, or from about 100 to about 10,000cP, or from about 100 to about 5,000 cP, or from about 500 to about15,000 cP, or from about 500 to about 10,000 cP, or from about 500 toabout 5,000 cP, or from about 1,000 to about 10,000 cP, wherein 1 cP=1mPa·sec.

In one or more embodiments, the semi-crystalline polymer may becharacterized by its viscosity at 190° C. In one or more embodiments,the semi-crystalline polymer may have a viscosity that is at least about100 cP (centipoise), or at least about 500 cP, or at least about 1,000cP, or at least about 1,500 cP, or at least about 2,000 cP, or at leastabout 3,000 cP, or at least about 4,000 cP, or at least about 5,000 cP.In these or other embodiments, the semi-crystalline polymer may becharacterized by a viscosity at 190° C. of less than about 100,000 cP,or less than about 75,000 cP, or less than about 50,000 cP, or less thanabout 25,000 cP, or less than about 20,000 cP, or less than about 15,000cP, or less than about 10,000 cP, or less than about 5,000 cP withranges from any lower limit to any upper limit being contemplated.

The polymers that may be used in the adhesive compositions disclosedherein generally include any of the polymers according to the processdisclosed in WO Publication No. 2013/134038. The triad tacticity andtacticity index of a polymer may be controlled by the catalyst, whichinfluences the stereoregularity of propylene placement, thepolymerization temperature, according to which stereoregularity can bereduced by increasing the temperature, and by the type and amount of acomonomer, which tends to reduce the length of crystalline propylenederived sequences. Such polymers made in accordance with WO PublicationNo. 2013/134038, when subjected to Temperature Rising ElutionFractionation, exhibit: a first fraction that is soluble at −15° C. inxylene, the first fraction having an isotactic (mm) triad tacticity ofabout 70 mol % to about 90 mol %; and a second fraction that isinsoluble at −15° C. in xylene, the second fraction having an isotactic(mm) triad tacticity of about 85 mol % to about 98 mol %. The contentsof WO Publication No. 2013/134038 and its parent application U.S. PatentApplication Ser. No. 61/609,020 filed Mar. 9, 2012, are bothincorporated herein in their entirety.

Polymers and blended polymer products are also provided. In anyembodiment, one or more of the polymers described herein may be blendedwith another polymer, such as another polymer described herein, toproduce a physical blend of polymers.

Catalysts/Activators

The polymers described herein may be prepared using one or more catalystsystems. As used herein, a “catalyst system” comprises at least atransition metal compound, also referred to as catalyst precursor, andan activator. Contacting the transition metal compound (catalystprecursor) and the activator in solution upstream of the polymerizationreactor or in the polymerization reactor of the process described aboveyields the catalytically active component (catalyst) of the catalystsystem. Any given transition metal compound or catalyst precursor canyield a catalytically active component (catalyst) with variousactivators, affording a wide array of catalysts deployable in theprocesses of the present invention. Catalyst systems of the presentinvention comprise at least one transition metal compound and at leastone activator. However, catalyst systems of the current disclosure mayalso comprise more than one transition metal compound in combinationwith one or more activators. Such catalyst systems may optionallyinclude impurity scavengers. Each of these components is described infurther detail below.

The triad tacticity and tacticity index of the polymer may be controlledby the catalyst, which influences the stereoregularity of propyleneplacement, the polymerization temperature, according to whichstereoregularity can be reduced by increasing the temperature, and bythe type and amount of a comonomer, which tends to reduce the length ofcrystalline propylene derived sequences.

In any embodiment, the catalyst systems used for producingsemi-crystalline polymers may comprise a metallocene compound. In anyembodiment, the metallocene compound may be a bridged bisindenylmetallocene having the general formula (In¹)Y(In²)MX₂, where In¹ and In²are identical substituted or unsubstituted indenyl groups bound to M andbridged by Y, Y is a bridging group in which the number of atoms in thedirect chain connecting In¹ with In² is from 1 to 8 and the direct chaincomprises C, Si, or Ge; M is a Group 3, 4, 5, or 6 transition metal; andX₂ are leaving groups. In¹ and In² may be substituted or unsubstituted.If In¹ and In² are substituted by one or more substituents, thesubstituents are selected from the group consisting of a halogen atom,C₁ to C₁₀ alkyl, C₅ to C₁₅ aryl, C₆ to C₂₅ alkylaryl, and Si-, N- orP-containing alkyl or aryl. Each leaving group X may be an alkyl,preferably methyl, or a halide ion, preferably chloride or fluoride.Exemplary metallocene compounds of this type include, but are notlimited to, μ-dimethylsilylbis(indenyl) hafnium dimethyl andμ-dimethylsilylbis(indenyl) zirconium dimethyl.

In any embodiment, the metallocene compound may be a bridged bisindenylmetallocene having the general formula (In¹)Y(In²)MX₂, where In¹ and In²are identical 2.4-substituted indenyl groups bound to M and bridged byY, Y is a bridging group in which the number of atoms in the directchain connecting In¹ with In² is from 1 to 8 and the direct chaincomprises C, Si, or Ge, M is a Group 3, 4, 5, or 6 transition metal, andX₂ are leaving groups. In¹ and In² are substituted in the 2 position bya C₁ to C₁₀ alkyl, preferably a methyl group and in the 4 position by asubstituent selected from the group consisting of C₅ to C₁₅ aryl, C₆ toC₂₅ alkylaryl, and Si-, N- or P-containing alkyl or aryl. Each leavinggroup X may be an alkyl, preferably methyl, or a halide ion, preferablychloride or fluoride. Exemplary metallocene compounds of this typeinclude, but are not limited to,(dimethylsilyl)bis(2-methyl-4-(3,′5′-di-tert-butylphenyl)indenyl)zirconium dimethyl,(dimethylsilyl)bis(2-methyl-4-(3,′5′-di-tert-butylphenyl)indenyl)hafnium dimethyl, (dimethylsilyl)bis(2-methyl-4-naphthylindenyl)zirconium dimethyl, (dimethylsilyl)bis(2-methyl-4-naphthylindenyl)hafnium dimethyl, (dimethylsilyl)bis(2-methyl-4-(N-carbazyl)indenyl)zirconium dimethyl, and(dimethylsilyl)bis(2-methyl-4-(N-carbazyl)indenyl) hafnium dimethyl.

Alternatively, in any embodiment, the metallocene compound maycorrespond to one or more of the formulas disclosed in U.S. Pat. No.7,601,666. Such metallocene compounds include, but are not limited to,dimethylsilylbis(2-(methyl)-5,5,8,8-tetramethyl-5,6,7,8-tetrahydrobenz(f)indenyl)hafnium dimethyl, diphenylsilylbis(2-(methyl)-5,5,8,8-tetramethyl-5,6,7,8-tetrahydrobenz(f)indenyl)hafnium dimethyl, diphenylsilylbis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydrobenz(f)indenyl) hafniumdimethyl, diphenylsilylbis(2-(methyl)-5,5,8,8-tetramethyl-5,6,7,8-tetrahydrobenz(f) indenyl)zirconium dichloride, and cyclo-propylsilylbis(2-(methyl)-5,5,8,8-tetramethyl-5,6,7,8-tetrahydrobenz(f) indenyl)hafnium dimethyl.

In any embodiment, the activators of the catalyst systems used toproduce semi-crystalline polymers may comprise a cationic component. Inany embodiment, the cationic component may have the formula [R¹R²R³AH]⁺,where A is nitrogen, R¹ and R² are together a —(CH₂)_(a)— group, where ais 3, 4, 5, or 6 and form, together with the nitrogen atom, a 4-, 5-,6-, or 7-membered non-aromatic ring to which, via adjacent ring carbonatoms, optionally one or more aromatic or heteroaromatic rings may befused, and R³ is C₁, C₂, C₃, C₄, or C₅ alkyl, or N-methylpyrrolidiniumor N-methylpiperidinium. Alternatively, in any embodiment, the cationiccomponent has the formula [R_(n)AH_(4-n)]⁺, where A is nitrogen, n is 2or 3, and all R are identical and are C₁ to C₃ alkyl groups, such as forexample trimethylammonium, trimethylanilinium, triethylammonium,dimethylanilinium, or dimethylammonium.

A particularly advantageous catalyst that may be employed in anyembodiment is illustrated in Formula I.

In any embodiment, M is a Group IV transition metal atom, preferably aGroup IVB transition metal, more preferably hafnium or zirconium, and Xare each an alkyl, preferably methyl, or a halide ion, preferablychloride or fluoride. Methyl or chloride leaving groups are mostpreferred. In any embodiment, R1 and R2 may be independently selectedfrom the group consisting of hydrogen, phenyl, and naphthyl. R1 ispreferably the same as R2. Particularly advantageous species of FormulaI are dimethylsilyl bis(2-methyl-4-phenylindenyl) zirconium dichloride,dimethylsilyl bis(2-methyl-4-phenylindenyl) zirconium dimethyl,dimethylsilyl bis(2-methyl-4-phenylindenyl) hafnium dichloride, anddimethylsilyl bis(2-methyl-4-phenylindenyl) hafnium dimethyl.

Any catalyst system resulting from any combination of a metallocenecompound, a cationic activator component, and an anionic activatorcomponent mentioned in this disclosure shall be considered to beexplicitly disclosed herein and may be used in accordance with thepresent invention in the polymerization of one or more olefin monomers.Also, combinations of two different activators can be used with the sameor different metallocene(s).

In any embodiment, the activators of the catalyst systems used toproduce the semi-crystalline polymers may comprise an anionic component,[Y]⁻. In any embodiment, the anionic component may be a non-coordinatinganion (NCA), having the formula [B(R⁴)⁴]⁻, where R⁴ is an aryl group ora substituted aryl group, of which the one or more substituents areidentical or different and are selected from the group consisting ofalkyl, aryl, a halogen atom, halogenated aryl, and haloalkylaryl groups.The substituents may be perhalogenated aryl groups, or perfluorinatedaryl groups, including, but not limited to, perfluorophenyl,perfluoronaphthyl and perfluorobiphenyl.

Together, the cationic and anionic components of the catalysts systemsdescribed herein form an activator compound. In any embodiment, theactivator may be N,N-dimethylanilinium-tetra(perfluorophenyl)borate,N,N-dimethylanilinium-tetra(perfluoronaphthyl)borate,N,N-dimethylanilinium-tetrakis(perfluorobiphenyl)borate,N,N-dimethylanilinium-tetrakis(3,5-bis(trifluoromethyl)phenyl)borate,triphenylcarbenium-tetra(perfluorophenyl)borate,triphenylcarbenium-tetra(perfluoronaphthyl)borate,triphenylcarbenium-tetrakis(perfluorobiphenyl)borate, ortriphenylcarbenium-tetrakis(3,5-bis(trifluoromethyl)phenyl)borate.

A non-coordinating anion activator may be employed with the catalyst. Aparticularly advantageous activator isdimethylaniliniumtetrakis(heptafluoronaphthyl) borate.

Suitable activators for the processes of the present invention alsoinclude aluminoxanes (or alumoxanes) and aluminum alkyls. Without beingbound by theory, an alumoxane is typically believed to be an oligomericaluminum compound represented by the general formula (R^(x)—Al—O)_(n),which is a cyclic compound, or R^(x)(R^(X)—Al—O)_(n)AlR^(x) ₂, which isa linear compound. Most commonly, alumoxane is believed to be a mixtureof the cyclic and linear compounds. In the general alumoxane formula,R^(x) is independently a C₁-C₂₀ alkyl radical, for example, methyl,ethyl, propyl, butyl, pentyl, isomers thereof, and the like, and n is aninteger from 1-50. In any embodiment. R^(x) may be methyl and n may beat least 4. Methyl alumoxane (MAO), as well as modified MAO containingsome higher alkyl groups to improve solubility, ethyl alumoxane,iso-butyl alumoxane, and the like are useful for the processes disclosedherein.

Further, the catalyst systems suitable for use in the present inventionmay contain, in addition to the transition metal compound and theactivator described above, additional activators (co-activators), and/orscavengers. A co-activator is a compound capable of reacting with thetransition metal complex, such that when used in combination with anactivator, an active catalyst is formed. Co-activators includealumoxanes and aluminum alkyls.

In any embodiment, scavengers may be used to “clean” the reaction of anypoisons that would otherwise react with the catalyst and deactivate it.Typical aluminum or boron alkyl components useful as scavengers arerepresented by the general formula R^(x)JZ₂ where J is aluminum orboron, R^(x) is a C₁-C₂₀ alkyl radical, for example, methyl, ethyl,propyl, butyl, pentyl, and isomers thereof, and each Z is independentlyR^(x) or a different univalent anionic ligand such as halogen (Cl, Br,I), alkoxide (OR^(x)), and the like. Exemplary aluminum alkyls includetriethylaluminum, diethylaluminum chloride, ethylaluminium dichloride,tri-iso-butylaluminum, tri-n-octylaluminum, tri-n-hexylaluminum,trimethylaluminum, and combinations thereof. Exemplary boron alkylsinclude triethylboron. Scavenging compounds may also be alumoxanes andmodified alumoxanes including methylalumoxane and modifiedmethylalumoxane.

Solvents

The solvent used in the reaction system of the present invention may beany non-polymeric species capable of being removed from the polymercomposition by heating to a temperature below the decompositiontemperature of the polymer and/or reducing the pressure of thesolvent/polymer mixture. In any embodiment, the solvent may be analiphatic or aromatic hydrocarbon fluid.

Examples of suitable, preferably inert, hydrocarbon fluids are readilyvolatile liquid hydrocarbons, which include, for example, hydrocarbonscontaining from 1 to 30, preferably 3 to 20, carbon atoms. Preferredexamples include propane, n-butane, isobutane, mixed butanes, n-pentane,isopentane, neopentane, n-hexane, cyclohexane, isohexane, octane, othersaturated C₆ to C₈ hydrocarbons, toluene, benzene, ethylbenzene,chlorobenzene, xylene, desulphurized light virgin naphtha, and any otherhydrocarbon solvent recognized by those skilled in the art to besuitable for the purposes of this invention. Particularly preferredsolvents for use in the processes disclosed herein are n-hexane andtoluene.

The optimal amount of solvent present in combination with the polymer atthe inlet to the devolatilizer will generally be dependent upon thedesired temperature change of the polymer melt within the devolatilizer,and can be readily determined by persons of skill in the art. Forexample, the polymer composition may comprise, at the inlet of thedevolatilizer, from about 1 wt % to about 50 wt % solvent, or from about5 wt % to about 45 wt % solvent, or from about 10 wt % to about 40 wt %solvent, or from about 10 wt % to about 35 wt % solvent.

WO Publication No. 2013/134038 generally describes the catalysts,activators, and solvents used to prepare the polymer blend used in theadhesive compositions. The contents of WO Publication No. 2013/134038and its parent application U.S. Patent Application Ser. No. 61/609,020filed Mar. 9, 2012, are both incorporated herein in their entirety.

C. Tackifier

The term “tackifier” is used herein to refer to an agent that allows thepolymer of the composition to be more adhesive by improving wettingduring the application. Tackifiers may be produced frompetroleum-derived hydrocarbons and monomers of feedstock including talloil and other polyterpene or resin sources. Tackifying agents are addedto give tack to the adhesive and also to modify viscosity. Tack isrequired in most adhesive formulations to allow for proper joining ofarticles prior to the HMA solidifying.

“Softening Point” is the temperature, measured in ° C., at which amaterial will flow, as determined by ASTM E-28.

“Aromaticity” is determined by NMR spectroscopy and is measured in mol %of aromatic protons.

Although the exemplary formulations disclosed herein focus onformulations in which one or more tackifiers are blended with one ormore polymer blends, adhesive formulations having no tackifier orsubstantially no tackifier are also contemplated. In embodiments, othertackifiers may be used with the polymer blends of the inventionincluding, but not limited to, alkylphenolic, coumarone indene, otherhydrogenated or non-hydrogenated hydrocarbon resins, hydroxylatedpolyester resin, phenolic, pure monomer styrene, resin dispersion, rosinester, rosin, and terpene tackifiers.

D. Additives: Plasticizer, Wax, Antioxidant

The HMA composition can include other additives, e.g., plasticizers,waxes, antioxidants, and combinations thereof either alone or incombination with one or more tackifiers disclosed herein. The HMAcomposition can also include one or more polymer additives, either aloneor in combination with one or more tackifiers, plasticizers, waxes, orantioxidants, and combinations thereof as disclosed herein.

The term “polymer additive” is used herein to refer to a substancehaving a lower melt viscosity, measured at 190° C. and a highercrystallinity, as compared to the melt viscosity and crystallinity ofthe polymer blend used in the adhesive formulation. The polymer additiveis added to improve the performance attributes, including decreasing themelt viscosity, of the adhesive formulation to fit the end use of theformulation in a construction/laminate nonwoven or an elastic nonwoven.The addition of a polymer additive is not restricted to formulationsused in a construction/laminate nonwoven or an elastic nonwoven.

In embodiments, polymer additives may be used with the polymer blends ofthe invention including, but not limited to Polymer Additive A, abi-modal polymer having a Melt Viscosity at 190° C. of about 903 cP, DSCCrystallinity of about 41 J/g, a Shore Hardness C of about 35, EthyleneContent of about 8.2%, DSC Melting Point of about 111.35° C.

In embodiments, polymer additives may be used with the polymer blends ofthe invention including, but not limited to Vistamaxx™ 6202 availablefrom ExxonMobil Chemical. Vistamaxx™ 6202 propylene-based elastomer isan olefin elastomer having a Density of 0.863 g/cm3, Melt Index (at 190°C./2.16 kg) of 9.1 g/10 min, Melt Mass-Flow Rate of 20 g/10 min,Ethylene Content of 15 wt %, Shore Hardness A of 66. In embodiments,polymer additives may be used with the polymer blends of the inventionincluding, but not limited to Kraton™ G SEBS(styrene-ethylene/butylene-styrene) grade polymers available from KratonPolymers located in Houston, Tex.

The term “plasticizer” is used herein to refer to a substance thatimproves the fluidity of a material. Useful commercial availableplasticizers include Primol™ 352, Krystol™ 550, and Nyflex™ 222B.Primol™ 352 is a white oil available from ExxonMobil Chemical. Krystol™550 is a white oil available from Petro-Canada Lubricants. Nyflex™ 222Bis a solvent refined naphthenic oil available from Nynas AB, located inStockholm, Sweden.

The term “antioxidant” is used herein to refer to high molecular weighthindered phenols and multifunctional phenols. A useful commerciallyavailable antioxidant is Irganox™ 1010. Irganox 1010 is a hinderedphenolic antioxidant available from BASF SE Corporation located inLudwigshafen, Germany. The invention is not limited to Irganox 1010 asthe antioxidant. In embodiments, other antioxidants that may be usedwith the polymer blends of the invention, including, but are not limitedto amines, hydroquinones, phenolics, phosphites, and thioesterantioxidants.

The term “wax” is used herein to refer to a substance that tweaks theoverall viscosity of the adhesive composition. The primary function ofwax is to control the set time and cohesion of the adhesive system.Adhesive compositions of the present invention may comprise paraffin(petroleum) waxes and microcrystalline waxes. In embodiments, theadhesive compositions of the present invention may comprise no wax. Inembodiments, waxes may be used with the polymer blends of the inventionincluding, but not limited to, Castor Oil derivatives (HCO-waxes),ethylene co-terpolymers, Fisher-Tropsch waxes, microcrystalline,paraffin, polyolefin modified, and polyolefin.

E. Applications of Polyolefin Adhesive Compositions

The adhesive formulations disclosed herein can be used in variousnonwoven construction applications including, but not limited to,hygiene products such as baby diapers, adult diapers, incontinenceproducts or devices, absorbent articles, panty liners, and sanitarynapkins. The adhesive formulations disclosed herein can also be used invarious nonwoven elastic applications including, but not limited to,hygiene products such as wound care dressings for human or veterinarymedicine. As the hygiene industry is continuing to move to products,articles, and devices with thinner gauge films and thinner nonwovenmaterials, the industry is continuing to seek adhesive formulations thatcan be applied over a broad application temperature range, forversatility of an adhesive formulation in more than one end use product,article, device, and combinations thereof. The adhesive formulationsdescribed herein, having a high polymer load, provide a desiredcombination of physical properties such as stable adhesion over timeindicative of broad application temperature ranges and machinecoatability and therefore can be used in nonwoven applications includinghygiene products disclosed herein. It should be appreciated that theadhesive formulations of the present disclosure, while being well suitedfor use in hygiene nonwoven products, may also find utility in otherapplications as well.

In embodiments, one or more adhesive formulations can be used in baby oradult diapers, incontinence product, or training pants. One or moreadhesive formulations disclosed herein may be used alone or incombination with other additives for affixing and or securing differentlayers or different components of a disposable diaper, incontinenceproduct, or training pant construction. The construction of a diaper,incontinence product, or training pant can be accomplished in anyconventional manner known in the art.

In a common construction, a diaper, incontinence product, or trainingpant includes a pant body having a front section, a back section, acrotch section, two elastic sections each having a front elastic memberand a back elastic member, two leg openings and a waist opening, abacksheet and a topsheet, a waistband and two leg bands, a waistborderand two leg borders, an absorbent article, and optionally a fasteningdevice having a quick-remove peelable layer on the fastening device whenthe diaper, incontinence product, or training pant is not in use.Certain non-limiting examples of using one or more adhesive formulationsof the present disclosure in a diaper, incontinence product, or trainingpant include attaching the sides of the front section to the backsection, attaching the crotch section to the front section and the backsection, attaching the topsheet to the front layer, attaching thebacksheet to the back layer, attaching the absorbent article to thecrotch section, attaching each of the leg bands to each of the legopenings of the topsheet and backsheet, attaching each of the legborders to each of the leg bands, attaching the waistband to the topsection of the top sheet and the top section of the backsheet, attachingthe waistborder to the waistband, attaching the quick-remove peelablelayer to the fastening device, and attaching the fastening device to thewaistborder.

In embodiments, one or more adhesive formulations can be used insanitary napkins or panty liners. As used herein, the term “sanitarynapkin” refers to an externally positioned, disposable absorbent articlein the form of a catamenial device, configured for the absorption ofbody fluids such as menses. As used herein, the term “panty liner”refers to an externally positioned, disposable absorbent article havinga thinner gauge and a narrower width than a sanitary napkin that can beconfigured for the absorption of body fluids. The construction of asanitary napkin or panty liner can be accomplished in any conventionalmanner known in the art.

In a common construction, a sanitary napkin or panty liner includes afront body having an absorbent article, back body to be positioned onthe undergarment of the wearer, a quick-remove peelable protectablelayer covering the back body when the sanitary napkin or panty liner isnot in use, optionally two side wing projections on either side of thefront body and a quick-remove peelable protective layer covering each ofthe two side wing projections when the sanitary napkin or panty liner isnot in use. Certain non-limiting examples of using one or more adhesiveformulations of the present disclosure in a sanitary napkin or pantyliner include attaching an absorbent article to the front body,attaching the front body to the back body, attaching a quick-removepeelable protective layer to the back body, attaching the two side wingprojections on the front body, and attaching a quick-remove peelableprotective layer to each of the two side wing projections on the frontbody.

In embodiments, one or more adhesive formulations can be used in a woundcare dressing for human or veterinary medicine. As used herein, the term“wound care dressing” refers to wet, dry, or a combination of wet anddry, gauze used at or around a wound site to help wound healing. Theconstruction of a wound care dressing can be accomplished in anyconventional manner known in the art. In a common construction, a woundcare dressing includes a top layer that is visible to the patient and abottom layer that is in contact with the wound, an absorbent article, anadhesive coating the bottom layer, and a quick-remove peelableprotective layer covering the bottom layer when the wound care dressingis not in use. Certain non-limiting examples of using one or moreadhesive formulations of the present disclosure in a wound care dressinginclude attaching an absorbent article to the bottom layer, attachingthe bottom layer to the top layer, attaching the quick-remove peelableprotective layer to the bottom layer, and attaching the adhesive coatingto the bottom layer.

Specific Embodiments

The invention may also be understood with relation to the followingspecific embodiments:

Paragraph A: an adhesive composition comprising: (a) a polymer blendcomprising a first propylene-based polymer, wherein the firstpropylene-based polymer is a homopolymer of propylene or a copolymer ofpropylene and ethylene or a C₄ to C₁₀ alpha-olefin; a secondpropylene-based polymer, wherein the second propylene-based polymer is ahomopolymer of propylene or a copolymer of propylene and ethylene or aC₄ to C₁₀ alpha-olefin; wherein the second propylene-based polymer isdifferent than the first propylene-based polymer; wherein the polymerblend has a melt viscosity, measured at 190° C. of about 100 to about6,000 cP and wherein, when subjected to Temperature Rising ElutionFractionation, the polymer blend exhibits: a first fraction that issoluble at −15° C. in xylene, the first fraction having an isotactic(mm) triad tacticity of about 70 mol % to about 90 mol %; and a secondfraction that is insoluble at −15° C. in xylene, the second fractionhaving an isotactic (mm) triad tacticity of about 85 mol % to about 98mol %; wherein the polymer blend is present in the amount of about 50 toabout 80 wt %/o of the adhesive composition; and (b) a tackifier;wherein the adhesive composition has a melt viscosity, measured at 140°C. of about 50 to about 5,500 cP.

Paragraph B: The adhesive composition of Paragraph A, wherein thetackifier has a softening point, as determined by ASTM E-28, of about 80to about 145° C.

Paragraph C: The adhesive composition of Paragraph A, wherein thetackifier has an aromaticity of about 0 to about 15 mol % aromaticprotons.

Paragraph D: The adhesive composition of Paragraph A, wherein thetackifier may be a single tackifier or a blend of one or moretackifiers.

Paragraph E: The adhesive composition of Paragraph A, further comprisingan antioxidant and a plasticizer.

Paragraph F: The adhesive composition of Paragraph A, further comprisinga wax present in the amount of less than about 10 wt % of the adhesivecomposition.

Paragraph G: The adhesive composition of Paragraph A, further comprisingone or more polymer additives having a lower total melt viscosity,measured at 190° C., and higher total crystallinity, as compared to themelt viscosity and crystallinity of the polymer blend.

Paragraph H: The adhesive composition of Paragraph A, wherein theadhesive composition has a peel strength, as determined by ASTM D-903,that does not vary by more than about 10% over an applicationtemperature of about 110° C. to 190° C.

Paragraph I: The adhesive composition of Paragraph A, wherein thepolymer blend has a heat of fusion of between about 5 to about 40 J/g,preferably about 10 to about 30 J/g.

Paragraph J: The adhesive composition of Paragraph A, wherein the meltviscosity of the adhesive composition, measured at 180° C., does notvary by more than about 10% for up to about 48 hours.

Paragraph K: An article comprising the adhesive composition of ParagraphA.

Paragraph L: An article of Paragraph K wherein the adhesive compositionadheres one or more substrates, and wherein at least one of the one ormore substrates comprises paper, cardboard, plastic, nonwoven, metal,wood, other natural fiber based material, or combinations thereof.

Paragraph M: An adhesive composition comprising: (a) a polymer blendcomprising a first propylene-based polymer, wherein the firstpropylene-based polymer is a homopolymer of propylene or a copolymer ofpropylene and ethylene or a C₄ to C₁₀ alpha-olefin; a secondpropylene-based polymer, wherein the second propylene-based polymer is ahomopolymer of propylene or a copolymer of propylene and ethylene or aC₄ to C₁₀ alpha-olefin; wherein the second propylene-based polymer isdifferent than the first propylene-based polymer; wherein the polymerblend has a melt viscosity, measured at 190° C. of about 6,000 to about60,000 cP; and wherein, when subjected to Temperature Rising ElutionFractionation, the polymer blend exhibits: a first fraction that issoluble at −15° C. in xylene, the first fraction having an isotactic(mm) triad tacticity of about 70 mol % to about 90 mol %; and a secondfraction that is insoluble at −15° C. in xylene, the second fractionhaving an isotactic (mm) triad tacticity of about 85 mol % to about 98mol %; wherein the polymer blend is present in the amount of about 30 toabout 60 wt % of the adhesive; and (b) a tackifier; wherein the adhesivecomposition has a melt viscosity, measured at 140° C. of about 1,500 toabout 15,000 cP.

Paragraph N: The adhesive composition of Paragraph M, wherein thetackifier has a softening point, as determined by ASTM E-28, of about 80to about 145° C.

Paragraph O: The adhesive composition of Paragraph M, wherein thetackifier has an aromaticity of about 0 to about 15 mol % aromaticprotons.

Paragraph P: The adhesive composition of Paragraph M, wherein thetackifier may be a single tackifier or a blend of one or moretackifiers.

Paragraph Q: The adhesive composition of Paragraph M, further comprisingan antioxidant and a plasticizer.

Paragraph R: The adhesive composition of Paragraph M, further comprisinga wax present in the amount of less than about 10 wt % of the adhesivecomposition.

Paragraph S: The adhesive composition of Paragraph M, further comprisingone or more polymer additives having a lower total melt viscosity,measured at 190° C. and higher total crystallinity, as compared to themelt viscosity and crystallinity of the polymer blend.

Paragraph T: The adhesive composition of Paragraph M, wherein theadhesive composition has a peel strength, as determined by ASTM D-903,that does not vary by more than about 10% over an applicationtemperature of about 110° C. to about 190° C.

Paragraph U: The adhesive composition of Paragraph M, wherein thepolymer blend has a heat of fusion of between about 5 to about 40 J/g,preferably about 10 to about 30 J/g.

Paragraph V: The adhesive composition of Paragraph M, wherein the meltviscosity of the adhesive composition, measured at 180° C., does notvary by more than about 10% for up to about 48 hours.

Paragraph W: An article comprising the adhesive composition of ParagraphM.

Paragraph X: An article of Paragraph W wherein the adhesive compositionadheres one or more substrates, and wherein at least one of the one ormore substrates comprises paper, cardboard, plastic, nonwoven, metal,wood, other natural fiber based material, or combinations thereof.

EXAMPLES

“Peel” or “Peel Strength” is a measure of the average force to pullapart two bonded materials, measured in grams. Peel is tested in aT-Peel fashion on a slip/peel tester from IMASS Inc. at 12 in/min, asdetermined by ASTM D-903.

“Application Temperature” is the temperature, in ° C., at which anadhesive formulation is applied to bond two substrates together.

“Failure Mode” is used to describe the location of the adhesive once apeel or delamination test is performed. Adhesive failure (AF) is definedas 100% of the adhesive remaining to the original substrate. Adhesivetransfer (AT) is defined as 100% of the adhesive transferring to theopposite substrate. Cohesive failure (CF) is defined as an adhesivesplit where there is adhesive on both substrates.

To apply the adhesive to the substrate, one or more polymer blends,optionally with other additives, including one or more tackifiers, oneor more polymer additives, one or more waxes, and one or moreantioxidants, is preheated at the application temperature until thepolymer is molten. The molten material is poured into a hot melt tankand allowed to equilibrate. The pump speed is set and the add-on iscalculated based on the amount of adhesive that passes through thenozzle in a given time.

In a pilot plant, propylene-ethylene copolymers are produced by reactinga feed stream of propylene with a feed stream of ethylene in thepresence of a metallocene catalyst. Table 1 shows properties of polymerblends used in the Examples, and these polymer blends are generallyproduced in accordance with the method disclosed in WO Publication No.2013/134038. The adhesive blends presented in the Tables below areprepared by preheating the tackifier, oil, antioxidant, and otheradditives to 177° C. One or more polymer blends is slowly added in aheated mantle at 177° C. to the molten liquid of tackifier, oil,antioxidant, and other additives, until all of the polymer has beenadded and is completed blended. The components are blended by manualstirring using a spatula until all polymer pellets are melted and themixture is homogeneous. The components are stirred for an additional 10minutes. The adhesive blend is removed from the heating mantle, andpoured onto release paper. After the adhesive blend solidifies, it iscut into small pieces for testing.

The comparative example (referred to herein as Comparative) is thecommercially available premium grade of hot melt adhesives used fornonwoven applications by H. B. Fuller: D3166.

Table 1 lists the polymer blends used in the examples of the invention.The term “Bi-modal” as used in Table 1 is used to refer to polymers orpolymer blends which have more than one compositional peak when measuredby GPC, DSC, or TREF. The invention is not limited to the polymer blendsdisclosed in Table 1.

Table 2 shows peel strength and failure mode of 8 adhesive formulationsand the Comparative formulation. The initial peel strength of theComparative formulation is similar to the 1 hour and 24 hour peelstrength values. In contrast, peel strength of the inventive adhesiveformulations generally increase over time, i.e. building ultimatestrength over time, for adhesive formulations having polymer blends witha heat of fusion greater than 23 (such as Example 5A or 7A) or within 24hours for polymers with a heat of fusion of less than 24 (Examples 4Aand 9A). The examples indicate a correlation between heat of fusion ofthe polymer blend used in the formulation and peel strength. Polymersblends having low heat of fusion, such as Example 6, are softer andlower in cohesion but can be formulated into nonwoven applications.Polymer blends having higher heat of fusion, such as Example 8A, displaydecreasing peel strength over time as the crystallinity builds fasterthan adhesion. Polymer blends with very high heat of fusion, such asExample 3A, show little to no adhesion to the surface and the adhesivetransferred to the opposite substrate, i.e. the adhesive was coated tothe backsheet but when it peeled apart all of the adhesive hadtransferred to the nonwoven fibers. The adhesive formulations of Table 2can be used in construction/laminated nonwovens and for elasticnonwovens alike, preferably for nonwoven construction articles,products, and devices. The formulations may also find utility in otheraspects of nonwoven construction.

Table 3 shows peel strength of 12 adhesive formulations having one ormore polymer blends. Most of the examples do not have any tackifier,wax, or other additives. Examples 1B and 2B are representative ofadhesive formulations used by some manufacturers in constructionnonwoven applications. Accordingly, for Table 3 Examples 1B and 2B arecomparative examples. Examples 3B-11B show adhesive formulations havingonly one or more polymer blends with unfavorable changing peel strengthover time, as compared to Examples 1B and 2B. Furthermore, Examples3B-11B have the limitation of lacking adequate adhesion, as indicated bythe failure mode, because of not having any tackifier. Example 12B,having a tackifier, displayed superior performance properties includinggood adhesion and broad application temperature ranges, as compared toExamples 3B-11B. The adhesive formulations of Table 3 can be used inconstruction/laminated nonwovens and for elastic nonwovens alike,preferably for nonwoven construction articles, products, and devices.The formulations may also find utility in other aspects of nonwovenconstruction.

Table 4 shows peel strength of 9 adhesive formulations. The adhesiveformulation of Example 1C has 100 wt % of a polymer blend as compared tothe formulations of Examples 5C-7C having 50 wt % polymer blend. Thevariability of the polymer loading in the adhesive formulation of theexamples, while not compromising performance properties including peelstrength, indicate that the formulations of the invention can beprepared to impart flexibility based on the end use application. Table 4also shows the viscosities of the polymer blends used in the adhesiveformulations. Generally, polymer blends having viscosity lower than6,000 cP, (such as Examples 1C, 2C, 3C, 4C, 7C, and 8C) can make up fromabout 50 to about 100 wt % of the adhesive formulation to maintain goodperformance properties. Generally, polymer blends having viscositygreater than or equal to about 6.000 cP, (such as Examples 5C and 6C)can make up from about 30 to about 70 wt % of the adhesive formulationto maintain good performance properties. Example 9C, having a viscosityof 8,000 cP and making up 70 wt % of the adhesive formulation displayedunfavorable decreasing of peel strength over time. However, the presentinvention does not exclude the adhesive formulation of Example 9C as oneof ordinary skill in formulating adhesives could reformulate thecomposition to result in favorable peel strength values. The adhesiveformulations of Table 4 can be used in construction/laminated nonwovensand for elastic nonwovens alike, preferably for nonwoven constructionarticles, products, and devices. The formulations may also find utilityin other aspects of nonwoven construction.

Table 5 shows peel strength, viscosities, and failure modes of 17adhesive formulations. All adhesive formulations include one or moretackifiers and optionally a plasticizer. Adhesive formulations havingone or more tackifiers with a Softening Point from about 80° C. to about145° C. and Aromaticity from about 0 to about 15 mol % aromatic protons,when mixed with one or more polymer blends, displayed superiorperformance properties indicating the versatile tackifiers that can beadded to the adhesive formulations. Table 5 also shows the viscosity ofthe adhesive formulations at 140° C. The adhesive formulations of Table5 can be used in construction/laminated nonwovens and for elasticnonwovens alike, preferably for nonwoven construction articles,products, and devices. The formulations may also find utility in otheraspects of nonwoven construction.

Table 6 shows adhesive formulations evaluated in FIG. 3.

Table 7 shows the peel strength and viscosity of an adhesive formulationhaving 50 wt % of a polymer blend, a tackifier, and an oil atapplication temperatures of 120° C., 140° C., 160° C. (Examples 1F, 2F,3F). Table 7 also shows the peel strength of viscosity of an adhesiveformulation having 35 wt % of the same polymer blend, 15 wt % of apolymer additive, a tackifier, and an oil, also at applicationtemperatures of 120° C., 140° C., 160° C. (Examples 4F, 5F, 6F). Theperformance attributes in Table 7 show that adding 15% of a polymeradditive in the adhesive formulation decreases viscosity of theformulation for all application temperatures and increases peel strengthfor all application temperatures. However, as shown by Examples 4F, 5F,and 6F, the addition of polymer additive increases the variability ofpeel strength over the application temperature range from 120 to 160°C., as compared to Examples 1F, 2F, and 3F.

Table 8 shows the peel strength, failure mode, and viscosities of anadhesive formulation having 50 wt % of a polymer blend, a tackifier, andan oil (Examples 1G, 2G, and 3G). The performance attributes in Table 8show that the selection of tackifier can alter the formulation viscosityand peel, including aged peel.

FIG. 1 shows the peel strength of an inventive adhesive formulationhaving 50 wt % Polymer Blend A and 40 wt % Escorez 5400 compared to theComparative adhesive at three different application temperatures: 120°C., 140° C., and 160° C. Advantageously, inventive adhesive formulationdemonstrate stable peel strength values at lower applicationtemperatures in contrast with the Comparative examples, whichunfavorably demonstrate decreasing peel strength at lower applicationtemperatures. The relatively stable peel strength of the inventiveadhesive formulation demonstrates that it can be used in a broaderapplication temperature window, for use in a wide range of nonwovenproducts including construction/laminated nonwovens and elasticnonwovens, as compared to the Comparative which would be limited tohigher application temperature uses. While the present invention is notdirected to a specific peel strength of the adhesive formulation, butrather is directed to stable peel strengths over different applicationtemperatures, the inventive adhesive formulation surprisingly showedimproved peel strength at lower application temperatures, in contrast tothe unfavorably decreasing peel strength of the Comparative formulationat lower application temperatures, thereby showing that the inventiveformulation may be used to impart strong bonding strength of one or moresubstrates at low application temperatures.

FIG. 2 shows the pump pressure and viscosities of an inventive adhesiveformulation having 50 wt % Polymer Blend A and 40 wt % Escorez 5400compared to the Comparative adhesive over three different applicationtemperatures: 120° C., 140° C., and 160° C. Typically, as thetemperature is lowered the viscosity increases and the measured pumppressure also increase. Increasing pump pressure typically results inpoor coating of the substrate with the adhesive, for example, whenspraying, the adhesive often has an erratic or irregular coatingpattern. Surprisingly, the inventive adhesive formulation displayedstable peel strength values at lower application temperatures, asindicated in FIG. 1, despite having a higher pump pressure and viscositycompared to the Comparative. Additionally, the inventive adhesiveformulation was sprayable at all application temperature ranges, whereasthe Comparative formulation was not sprayable at lower applicationtemperatures. This behavior indicates that inventive adhesiveformulation allows for a broader application temperature range.

FIG. 3 shows viscosities of adhesive formulations as determined whilethe adhesive formulation remained in a hot melt mixing tank at 180° C.Generally, adhesive formulations are applied to one or more substrates,via contact and/or contactless, e.g. spray, application techniqueswithin about 8 hours of preparing the formulation. In the event that anadhesive formulation is left in a hot melt mixing tank at 1800 beyond 8hours, it is desired that the viscosity of the adhesive formulationremains stable, for up to about 48 hours, i.e. 40 hours beyond thetypical time period during which the formulation would generally be usedin an application, so that the formulation does not deteriorate inperformance attributes, and is still as valuable as if it were appliedat 8 hours. Examples 1E, 2E, 3E, and 7E have stable viscosity from 0 to48 hours. This behavior indicates these adhesive formulations would notchange in application quality or induce charring that may result invisibly poor adhesive coating. Examples 4E, 5E, and 6E, having lowpolymer loading of the adhesive formulation around 20 to 25% (ascompared to higher loading of 40-80 wt % in the other Examples) showviscosity degradation as early as 2 hours, even prior to the 8 hour timeperiod that adhesive formulations would generally be kept in a hot meltmixing tank. FIG. 3 indicates that adhesive formulations having higherpolymer loading, i.e. above 25 wt %, have favorably stable viscositieswhen kept in hot melt mixing tanks up to about 48 hours.

TABLE 1 Viscosity DSC DSC Polymer at 190° C., Crystallinity, ShoreEthylene Melting Bi- Blend cP dH, J/g Hardness C Content, % Point, ° C.modal A 12,470 19.83 31 11.14 64.65 yes B 8,000 23.10 21 12.36 100.7 yesC 4,087 6.23 11 11.97 63.06 yes D 3,087 26.19 22 10.46 100.95 yes E11,550 12.95 23 12.3 64.6 yes F 4,268 33.95 33 10.6 83.57 yes G 37,65017.01 13.5 92.1 yes H Styrenic block copolymer with diene beingisoprene, having a styrene content of 30% and diblock content below 1%available from dexcopolymers. I Styrenic block copolymer with dienebeing isoprene, having a styrene content of 15% and diblock content of18% available from dexcopolymers. J Styrenic block copolymer with dienebeing butadiene, having a styrene content of 29% and diblock contentbelow 1% available from dexcopolymers. Rextac ™ 3,000 AmorphousPolyAlpha Olefin with medium ethylene content 2330 having a Tg of −29°C. and a Ring and Ball Softening Point of (Source: 141° C. Rextac LLClocated in Texas, USA) Rextac ™ 3,000 Amorphous PolyAlpha Olefin withmedium ethylene content 2730 having a Tg of −23° C. and a Ring and BallSoftening Point of (Source: 110° C. Rextac LLC located in Texas, USA)Licocene ™ 6,300 mPP wax having medium crystallinity, density of 0.89g/cm³. 2602 (at 170° C.) (Source: Clariant)

TABLE 2 Polymer Polymer Initial Peel 1 hr Peel 24 hr Peel Blend Blend(g)/ (g)/ (g)/ Adhesive Formulation TM dH Failure Failure Failure (wt %of the Adhesive) ° C. J/g Mode Mode Mode 1A Comparative 81 50.85110.83/CF 110/CF 114/CF 2A 80% Rextac ™ 2730/ 70 10 110.5/CF 112.8/CF113/CF 20% Eastotac ™ H-130W (coated at 160° C.) 3A 50% Licocene ™ 2602/86 39 75.2/50% 17/100% 6.5/AT 40% Escorez ™ 5400/ AT AT 10% Krystol ™550 4A 50% Polymer Blend A/ 65 19.9 64/CF 58.5/CF 91.5/CF 40% Escorez ™5400/ 10% Krystot ™ 550 5A 80% Polymer Blend D/ 101 29.73 112.8/CF125/CF 122.8/CF 20% Escorez ™ 5400 6A 80% Polymer Blend C/ 63 6.23100.2/CF 117/CF 114.8/CF 20% Escorez ™ 5400 7A 50% Polymer Blend B/ 10023.1 109/CF 115/CF 119/CF 40% Escorez ™ 5400/ 10% Krystol ™ 550 8A 70%Polymer Blend F/ 83 33.95 81/CF 54/CF 26/CF 20% Escorez ™ 5400/ 10%Krystol ™ 550 9A 50% Polymer Blend E/ 65 12.95 71.7/CF 71.3/CF 123.7/CF40% Escorez ™ 5400/ 10% Krystol ™ 550

TABLE 3 Polymer 24 hr Blend(s) Polymer Initial Peel 1 hr Peel PeelViscosity Blend(s) (g)/ (g)/ (g)/ Adhesive Formulation (cP) dH FailureFailure Failure (wt % of the Adhesive) at 190 C. J/g Mode Mode Mode 1B100% Rextac ™ 2730 150° C. 3,000 10 124/CF 128/CF 125/CF 2B 100%Rextac ™ 2730 160° C. 3,000 10 114/CF 121/CF 125/CF 3B Polymer Blend C4,087 6.23 85/CF 53/CF 32/CF 4B Polymer Blend D 2,930 29.73 38/CF18.5/CF 6/CF 5B 50% Polymer Blend C/ 2,930/4,087 29.73/6.23 36/CF 25/AF11/AF 50% Polymer Blend D 6B 65% Polymer Blend D/35% 2,930/4,08729.73/6.23 32/CF 20/AF 12/AF Polymer Blend C 7B 75% Polymer Blend D/25%2,930/4,087 29.73/6.23 40/AF 18/AF 7.5/AF Polymer Blend C 8B 90% PolymerBlend D/10% 2,930/4.087 29.73/6.23 50/CF 35/AF 19/AF Polymer Blend C 9B90% Polymer Blend C/10% 2,930/4,087 29.73/6.23 51/CF 36/CF 21/CF PolymerBlend D 10B 75% Polymer Blend C/25% 2,930/4,087 29.73/6.23 59/CF 45/CF17/CF Polymer Blend D 11B 50% Polymer Blend C/ 2,930/4,087 29.73/6.2379/CF 57/CF 51/CF 50% Polymer Blend D (slot coat) 12B 40% Polymer BlendC/ 2,930/4,087 29.73/6.23 184/CF 180/CF 171/CF 40% Polymer Blend D/ 20%Escorez ™ 5400

TABLE 4 Polymer Initial 24 hr 1 month Blend(s) Polymer Peel 1 hr PeelPeel Peel Viscosity Blend(s) (g)/ (g)/ (g)/ (g)/ Adhesive Formulation cPdH Failure Failure Failure Failure (wt % of the Adhesive) at 190 C. J/gMode Mode Mode Mode 1C 100% Polymer Blend C 4,087 6.23 144/CF 121/CF95/CF 75/CF 2C 80% Polymer Blend D/ 4,087 6.23 118/CF 114.7/CF 106.5/CF128/CF 20% Escorez ™ 5400 3C 70% Polymer Blend D/ 3,155 27.55 93/CF116/CF 124/CF 122/CF 30% Escorez ™ 5400 4C 70% Polymer Blend D/ 3,15527.55 59.2/CF 57.8/CF 73.2/CF 76/CF 20% Escorez ™ 5400/ 10% Krystol ™550 5C 50% Polymer Blend B/ 8,000 28.44 85.7/CF 102.5 101.8/CF 108/CF40% Escorez ™ 5400/ 10% Krystol ™ 550 6C 50% Polymer Blend E/ 11,55012.95 75.3/CF 69.3/CF 57/CF 60.2/CF 40% Escorez ™ 5400/ 10% Krystol ™550 7C 50% Polymer Blend C/ 2,930/4,087 29.73 79/CF 57/CF 51/CF 50%Polymer Blend D 8C 40% Polymer Blend C/ 2,930/4,087 29.73 184/CF 180/CF171/CF 40% Polymer Blend D/ 20% Escorez ™ 5400 9C 70% Polymer Blend B/8,000 28.44 87.3/CF 76.7/CF 76.5/CF 70/CF 20% Escorez ™ 5400/ 10%Krystol ™ 550

TABLE 5 Peel Initial 24 hr Aged 14 Peel 1 hr Peel Peel 1 month days atFormulation (g)/ (g)/ (g)/ Peel (g)/ 50 C./ Viscosity AdhesiveFormulation Failure Failure Failure Failure Failure (cP) (wt % of theAdhesive) Mode Mode Mode Mode Mode at 140 C.  1D 50% Polymer Blend B/109/CF 115/CF 119/CF 119/CF 118.5/CF 6,950 40% Escorez ™ 5400/ 10%Krystol ™ 550  2D 50% Polymer Blend B/ 124/AF 101/CF 118/CF 122/CF122/CF 7,000 20% Escorez ™ 5400/ 20% Escorez ™ 5600/ 10% Krystol ™ 550 3D 50% Polymer Blend B/ 145/CF 150/CF 159/CF 144/CF 130/CF 9,488 40%Escorez ™ 5340/ 10% Krystol ™ 550  4D 50% Polymer Blend B/ 94.83/CF87/CF 115/CF 116/CF 115/CF 5,938 40% Escorez ™ 5380/ 10% Krystol ™ 550 5D 50% Polymer Blend B/ 87/CF 88/CF 97/CF 85/CF 56/CF 6,520 40%Escorez ™ 5690/ 10% Krystol ™ 550  6D 80% Polymer Blend D/ 141/CF 135/CF158/CF 123/CF 125/CF 10,050 20% Escorez ™ 5400  7D 80% Polymer Blend D/126/CF 142/CF 141/CF 146/CF 115/CF 9,675 10% Escorez ™ 5400/ 10%Escorez ™ 5600  8D 80% Polymer Blend D/ 135/CF 162/CF 174/CF 135/CF117/CF 11,050 20% Escorez ™ 5340  9D 80% Polymer Blend D/ 115/CF 123/CF1112/CF 108/CF 101/CF 9,020 20% Escorez ™ 5380 10D 80% Polymer Blend D/126/CF 121/CF 121/CF 80/CF 56/CF 9,280 20% Escorez ™ 5690 11D 50%Polymer Blend B/ 91/CF 71/CF 23/CF 20 10/CF 6,713 40% Eastotac ™ H-130W/10% Krystol ™ 550 Peel Initial 24 hr Aged Peel 1 hr Peel Peel 14 days(g)/ (g)/ (g)/ 1 at 50 C./ Viscosity Adhesive Formulation FailureFailure Failure month Failure (cP) (wt % of the Adhesive) Mode Mode ModePeel (g) Mode at 140 C. 12D 50% Polymer Blend B/ 94/CF 98/CF 92/CF 8882/CF 5,430 40% Wingtack ™ 95/ 10% Kaystol ™ 550 13D 50% Polymer BlendB/ 104/CF 101/CF 96/CF 96 76/CF 5,820 40% Regalrez ™ 1100/ 10% Krystol ™550 14D 50% Polymer Blend B/ 10,500 40% Arkon ™ M135/ 10% Krystol ™ 55015D 50% Polymer Blend B/ 91/CF 72/CF 37/CF 23 18/CF 8,725 40% Eastotac ™H142/ 10% Krystol ™ 550 16D 50% Polymer Blend B/ 87/CF 93/CF 98/CF 11482/CF 6,250 40% Escorez ™ 5400/ 10% Sucrarez ™ 90 17D 50% Polymer BlendB/ 110/CF 91/CF 100/CF 79 22/CF 5,670 40% Zonatac ™ 98/ 10% Krystol ™550

TABLE 6 Adhesive Formulation (wt % of the Adhesive) 1E 50% Polymer BlendG/ 30% Escorez ™ 5400/ 20% Primol ™ 352/ 1% Irganox ™ 1010 2E 40%Polymer Blend G/ 40% Escorez ™ 5400/ 20% Primol ™ 352/ 1% Irganox ™ 10103E 50% Polymer Blend G/ 40% Escorez ™ 5400/ 10% Primol ™ 352/ 1%Irganox ™ 1010 4E 20% Polymer Blend H/ 57% Escorez ™ 5400/ 23% Nyflex ™222B/ 1% Irganox ™ 1010 5E 25% Polymer Blend I/ 55% Escorez ™ 5600/ 20%Primol ™ 352/ 1% Irganox ™ 1010 6E 20% Polymer Blend J/ 60% Escorez ™5600/ 20% Primol ™ 352/ 1% Irganox ™ 1010 7E 80% Rextac ™ 2330/ 20%Escorez ™ 5415 1% Irganox ™ 1010

TABLE 7 Peel (g) Application Formulation at 40° C./ Adhesive FormulationTemperature Viscosity Failure (wt % of the Adhesive) (° C.) (cP) Mode 1F50% Polymer Blend A/ 120 26,850 70.2/CF 40% Escorez ™ 5400/ 10%Krystol ™ 550 2F 50% Polymer Blend A/ 140 12,400  66/CF 40% Escorez ™5400/ 10% Krystol ™ 550 3F 50% Polymer Blend A/ 160 3,800  62/CF 40%Escorez ™ 5400/ 10% Krystol ™ 550 4F 35% Polymer Blend A/ 120 13,50080.8/CF 15% Polymer Additive A/ 40% Escorez ™ 5400/ 10% Krystol ™ 550 5F35% Polymer Blend A/ 140 6,350  72/CF 15% Polymer Additive A/ 40%Escorez ™ 5400/ 10% Krystol ™ 550 6F 35% Polymer Blend A/ 160 2,62565.8/CF 15% Polymer Additive A/ 40% Escorez ™ 5400/ 10% Krystol ™ 550

TABLE 8 Peel (g) Peel (g) Peel (g) at at Peel (g) at at 140° C./ 140°C./ Formulation Room 140° C./ Aged Aged 7 Viscosity Temperature Aged 1hr/ 24 hrs/ days/ Adhesive Formulation at 140° C. Aged <10 min/ FailureFailure Failure (wt % of the Adhesive) (cP) Failure Mode Mode Mode Mode1G 50% Polymer Blend B/ 10,440 33/CF 28/CF 13/CF 9/CF 40% Sylvalite ™RE100L/ 10% Krystol ™ 550/ 0.2% Irganox ™ 1010 2G 50% Polymer Blend B/14,950 5/CF 4/CF 2/CF 3/CF 40% Kristalex ™ 3100/ 10% Krystol ™ 550/ 0.2%Irganox ™ 1010 3G 50% Polymer Blend B/ 4,290 83/CF 78/CF 81/CF 90/CF 40%Foral ™ AX-E/ 10% Krystol ™ 550/ 0.2% Irganox ™ 1010 4G 100% D3166 6,32588/CF 101/CF 105/CF 129/CF

Certain embodiments and features have been described using a set ofnumerical upper limits and a set of numerical lower limits. It should beappreciated that ranges from any lower limit to any upper limit arecontemplated unless otherwise indicated. Certain lower limits, upperlimits, and ranges appear in one or more claims below. All numericalvalues are “about” or “approximately” the indicated value, and take intoaccount experimental error and variations that would be expected by aperson having ordinary skill in the art.

To the extent a term used in a claim is not defined above, it should begiven the broadest definition persons in the pertinent art have giventhat term as reflected in at least one printed publication or issuedpatent. Furthermore, all patents, test procedures, and other documentscited in this application are fully incorporated by reference to theextent such disclosure is not inconsistent with this application and forall jurisdictions in which such incorporation is permitted.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

We claim:
 1. An adhesive composition comprising: (a) a polymer blendcomprising a first propylene-based polymer, wherein the firstpropylene-based polymer is a homopolymer of propylene or a copolymer ofpropylene and ethylene or a C₄ to C₁₀ alpha-olefin; a secondpropylene-based polymer, wherein the second propylene-based polymer is ahomopolymer of propylene or a copolymer of propylene and ethylene or aC₄ to C₁₀ alpha-olefin; wherein the second propylene-based polymer isdifferent than the first propylene-based polymer; wherein the polymerblend has a melt viscosity, measured at 190° C. of about 100 to about6,000 cP and wherein, when subjected to Temperature Rising ElutionFractionation, the polymer blend exhibits: a first fraction that issoluble at −15° C. in xylene, the first fraction having an isotactic(mm) triad tacticity of about 70 mol % to about 90 mol %; and a secondfraction that is insoluble at −15° C. in xylene, the second fractionhaving an isotactic (mm) triad tacticity of about 85 mol % to about 98mol %; wherein the polymer blend is present in the amount of about 50 toabout 80 wt % of the adhesive composition; and (b) a tackifier, whereinthe adhesive composition has a melt viscosity, measured at 140° C. ofabout 50 to about 5,500 cP, wherein the adhesive composition has a peelstrength, as determined by ASTM D-903, that does not vary by more thanabout 10% over an application temperature of about 110° C. to 190° C.;and wherein the adhesive composition is free of plasticizer and wax. 2.The adhesive composition of claim 1, wherein the tackifier has asoftening point, as determined by ASTM E-28, of about 80 to about 145°C.
 3. The adhesive composition of claim 1, wherein the tackifier has anaromaticity of about 0 to about 15 mol % aromatic protons.
 4. Theadhesive composition of claim 1, wherein the tackifier may be a singletackifier or a blend of one or more tackifiers.
 5. The adhesivecomposition of claim 1, further comprising an antioxidant.
 6. Theadhesive composition of claim 1, further comprising one or more polymeradditives having a lower total melt viscosity, measured at 190° C., andhigher total crystallinity, as compared to the melt viscosity andcrystallinity of the polymer blend.
 7. The adhesive composition of claim1, wherein the polymer blend has a heat of fusion of between about 5 toabout 30 J/g.
 8. The adhesive composition of claim 1, wherein the meltviscosity of the adhesive composition, measured at 180° C., does notvary by more than about 10% for up to about 48 hours.
 9. An articlecomprising the adhesive composition of claim
 1. 10. An article of claim9, wherein the adhesive composition adheres one or more substrates, andwherein at least one of the one or more substrates comprises paper,cardboard, plastic, nonwoven, metal, wood, other natural fiber basedmaterial, or combinations thereof.